FAILURE MECHANISM OF TOPPING ROCK SLOPE USING JOINTED FINITE ELEMENT SIMULATION METHOD
WANG Yu1，2，LI Xiao1，WANG Mengyao3，LI Ming3，TIAN Hao3
(1. Key Laboratory of Engineering Geomechanics，Institute of Geology and Geophysics，Chinese Academy of Sciences，Beijing 100029，China；2. University of Chinese Academy of Sciences，Beijing 100049，China；3. Faculty of Engineering， China University of Geosciences，Wuhan，Hubei 430074，China)
摘要岩质边坡的倾倒破坏是地质环境中广泛存在的现象，通过模拟手段对边坡的响应规律进行科学准确预测显得尤为重要。采用基于强度折减法的节理有限元法(JFEM-SSR)对反倾层状边坡的变形破坏机制进行研究，该方法可同时考虑岩块和节理属性，并能充分体现岩层或岩块接触作用的非线性关系，在获得边坡应力、位移及塑性区的同时可以到边坡的稳定系数。首先，采用JFEM对R. E. Goodman和J. W. Bray提供的一个倾倒破坏的算例进行了模拟计算，证实该法应用于节理岩石边坡稳定性分析的合理性；然后，基于该方法，采用节理网络模型建立广乐高速公路一桥墩承台开挖边坡的地质模型，对其变形破坏机制及稳定性影响因素进行研究，重点探讨地下水渗流作用、地震作用、岩层倾角、岩面厚度对边坡变形破坏的影响，以便为工程决策提供依据。
Abstract：The topping failure of rock slope in geological environment is a widespread phenomenon，which is particularly important to predict the response by means of simulation method scientifically. Based on the shear strength reduction of jointed finite element method(JFEM-SSR)，the deformation and damage mechanisms of the topping rock slope are researched. The rock block and joints attributes can be considered at the same time by JFEM-SSR method；and nonlinear contact relation of rock layer or rock block can also be reflected fully. In the process of obtaining the stress，displacement and plastic zone of slope，the stability factor can be got. Firstly，a toppling failure examples provided by R. E. Goodman and J. W. Bray is calculated，proving the reliability of the method. Then，based on JFEM，discrete fracture network(DFN) is used to establish geological model of a cutting slope on Guangle highway，applying JFEM to analyze the deformation and failure mechanisms，influencing factors for stability. Influences of groundwater seepage，earthquake action，dip angle of rock stratum and the rock face thickness on the deformation and failure of slope are mainly discussed，so as to provide a basis for engineering design.
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2013, Vol. 32 
